But as soon as Erivo and Hudson, portraying jazz singer Shug Avery, started to sing the title song for a promotional video, he relaxed. Hudson, he saw, was enjoying herself.

The Color Purple: Cynthia Erivo wows critics in Broadway debut

Danielle Brooks is, by all accounts, a straight-up revelation as Sofia, the role Oprah made famous. It remakes a patchy musical as a thrilling one," he said.

The raunchy song she sings - Push da Button - is hers and hers alone. No female role is created solely for tits and ass, no male role is esoteric and inexplicable just for the sake of a chiseled jaw. This performance has Tony Award stamped all over it.

I am, of course, referring to myself in most of the above. The British actress is winning raves for her performance as Celie in the hit revival, overshadowing big-name co-star Jennifer Hudson.

But people entreat you to see The Color Purple. I want to see it because The Color Purple is that rare work that keeps coming to us in different forms and seeming welcome and necessary each time. Her face is a deeply incised mask of suffering and sorrow, her acting is plain and true and her singing is gorgeous beyond belief.

It felt that way as a book, and later as a movie. And I pointed out that, for her first Broadway show, it might be great not to have to carry the whole thing on her shoulders. Ms Erivo escorts us through these transformations with a subtle but tensile performance that parallels her character's evolution.